Women evidence worse substance use treatment outcomes than men (Greenfield et al., 2007), including higher rates of treatment dropout (Arfken et al., 2001; King & Canada, 2004; Sayre et al., 2002), lower treatment attendance (McCaul et al., 2001) and higher rates of post-treatment substance use relapse (Grella et al., 2006). Yet, substance abuse research often includes little attention to gender-specific factors relevant to particular vulnerabilities of female participants (Brady & Ashley, 2005; Greenfield et al., 2007). One factor especially relevant to risk of relapse for many female drug users is maternal stress; child care responsibilities and the associated stressors may significantly increase risk of substance use relapse, particularly during high- risk periods for relapse following substance abuse treatment. Further, although maternal factors have been a particular empirical and clinical focus regarding environmental risk factors for drug using women, but the large preponderance of this research is focused on the impact of maternal substance use on child outcomes, with little attention to drug use outcome for these women as an important target in its own right (cf., Pajulo et al., 2006). Accordingly, one promising factor that may help explain the maternal distress and substance use association when reintroduced to one's home environment following discharge from substance abuse treatment is maternal distress tolerance, or the ability to tolerate distress due to parenting issues. Indeed, one's ability to tolerate distress is associated with relapse following substance abuse treatment and length of abstinence attempts. However, despite its relevance to both substance use and parenting responses, little is known about the impact of low distress tolerance on substance using mothers. This may be due, at least in part, to the lack of distress tolerance assessment strategies that target directly the unique experience of maternal distress. To address the lack of research in this area, the following R21 attempts to provide an initial examination of maternal risk factors for substance use relapse, with a focus on the moderating role of distress tolerance. As a secondary aim, we explore a novel and ecologically valid measure of maternal distress tolerance to examine its utility over a standard distress tolerance task. Specifically, we will include 105 predominantly low-income, inner-city African American substance using mothers in their last week of residential drug use treatment that have a child in the critical age of 9 months to 4 years to examine the link between several indices of maternal distress and substance use outcomes with both general and maternal- specific measures of ability to tolerate distress as moderators of this relationship. PUBLIC HEALTH RELEVANCE: Maternal factors (i.e., parenting-related stressors) have been a particular empirical and clinical focus for drug using women, but the large preponderance of this research is focused on the impact of poor parenting and maternal substance use on child outcomes, with little attention to drug use outcome for these women as an important target in its own right. The current application proposes a novel framework for understanding risk factors for maternal relapse in the context of child-related stressors using the paradigm of distress tolerance. If maternal stress response is shown to be a mechanism underlying drug use outcomes, findings from this study have the potential to improve the prognosis for treatment outcome for high-risk mothers and positively impact the future health of their children.